1. Field of the Invention
The present invention relates to a negative pressure sensor abnormality detection apparatus, a control apparatus for an internal combustion engine and a control system.
2. Description of the Related Art
In the related art, a negative pressure sensor abnormality detection apparatus determining an abnormality in a negative pressure sensor is known (for example, see Japanese Laid-Open Patent Application No. 2011-122519). Such a negative pressure sensor abnormality detection apparatus has a negative pressure sensor that outputs a signal corresponding to a negative pressure, and detects the negative pressure based on the signal from the negative pressure sensor. Then, based on the negative pressure detection result, the negative pressure sensor abnormality detection apparatus determines whether the negative pressure sensor has an abnormality. Actually, if a state where the signal from the negative pressure sensor is out of a desired normal range continues greater than or equal to a predetermined period of time, the negative pressure sensor abnormality detection apparatus determines that the negative pressure sensor is in an abnormal condition.
Also, a vehicle having such a negative pressure sensor abnormality detection apparatus mounted has a brake booster assisting the driver's braking operation using a negative pressure generated through rotation of an internal combustion engine. Such a vehicle is an idling-stop vehicle automatically stopping an internal combustion engine when a predetermined stopping condition is satisfied, and, after the automatic stopping, automatically restarts the internal combustion engine when a predetermined restart condition is satisfied. Further, if it is determined that a negative pressure sensor is in an abnormal condition as mentioned above, automatic stopping of the internal combustion engine is inhibited.